Variable speed hydraulic clutches



July 12, 1955 J. R. THOMAS VARIABLE SPEED HYDRAULIC CLUTCHES 4Sheets-Sheet 1 Filed Sept. 3, 1954 y 12, 1955 J. R. THOMAS VARIABLESPEED HYDRAULIC CLUTCHES 4 Sheets-Sheet 2 INVENTOR,

July 12, 1955 J. R. THOMAS 2,712,867

VARIABLE SPEED HYDRAULIC CLUTCHES Filed Sept. 5, 1954 4 Sheets-Sheet 3f. fjj. f2

July 12, 1955 J. R. THOMAS 2,712,367

VARIABLE SPEED HYDRAULIC CLUTCHES Filed Sept. 5, 1954 4 Sheets-Sheet 4152%? $1?" 1"" 1M VnJve rmw/ q .oaooa 47 0 M1 .0: :4 .00505 0:54

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IN VENTURE y 20% Kw United States Patent Orifice VARIABLE SPEED BRAULICCLUTCHES John R. Thomas, iiichita, Karts, assignor to Thomas HydraulicSpeed Qcentrois, ino, Wichita, Kane, a corporation of Kansas ApplicationSeptember 3, 1954, Serial No. 454,155

13 Ciairns. (61. 19261) This invention is particularly directed toimproving the operation and efllciency of a variable speed hydraulicclutch of the type and character disclosed in my Patent No. 2,658,595issued November 10, 1 53, to which reference is made herein for purposesof complete disclosure of the present invention.

An object of the present invention is to provide a new and improvedhydraulic clutch transmission incorporating a porting of novel designand arrangement.

Another object of the present invention resides in the provision of anovel porting and discharge valve design and arrangement whereby agreater range and smoothness of controllability is attained.

Still another object of the present invention is found in providing ahydraulic clutch of the type disclosed in my prior Patent No. 2,658,595with improved inlet and ii outlet openings for the fluid circuitstherein and coordinating the movements or" the intake and dischargecontrol valves with respect to the improved inlet and outlet openingsthrough the single fluid flow control instrumentality.

A further object of the present invention resides in the provision of animproved fluid discharge control valve for particular restrictingcontrol of mid flow from the outlet openings of the fluid circuitsthrough the novel narrow annular slot in the outer peripheral portion ofthe body of the valve.

The various features of novelty whereby the present invention ischaracterized will hereinafter be pointed out with particularity in theappended claims, however,

for a full understanding of the invention and of its objects andadvantages, reference may be had to Patent No. 2,658,595 together withthe following description taken in connection with the accompanyingdrawings, exemplifying a preferred embodiment of the invention, wherein:

Fig. l is a longitudinal section through a hydraulic clutch embodying mypresent invention; the section corresponding to that shown in Fig. l ofsaid prior patent;

Fig. 2 is a vertical section of a modified form of one of the combinedair and oil intake control valves illustrated in Fig. 8 of said priorpatent but showing my improved discharge control valve;

Fig. 3 is a top plan view of one of the intake control valves;

Fig. 4 is a plan view of one of the fluid circuit inlet openings;

Fig. 5 is a plan view of one of the fluid circuit outlet openings;

Fig. 6 shows an outside elevation of the pump manifold;

Fig. 7 is an enlarged cross-section taken on line 7-7 of Pig. 6 showingone of the discharge ports of the manifold and a corresponding portionof the pump body and one of its discharge ports communicating with themanifold discharge port together with a portion of the novel dischargecontrol valve;

Fig. 8 is a cross-section taken on line 8-8 of Fig. 6

showing one of the air and oil inlet openings in the pump manifold valveseat;

Fig. 9 shows an end elevation of the novel discharge control valve inthe same enlarged scale as shown in Fig. 7;

Fig. 10 is a cross-section of the discharge control valve taken on line1l9lil of Fig. 9;

ll is ch 'l't showing comparative curves of a progressively increasedoil intal'e area or an inlet opening and the corresponding uniform andprogressively restricted discharge area of an outiet opening of a fluidcircuit during the full range or" mover t of the fiow controlrurnentality from neutral to 11 position; the curves 2 of the newimproved porting;

12 shows comparative curves of the open areas t outiet openings ofporting disclosed in Patent No. 2,658,595 during full range of movementof the flow control instrumentality from neutral to high position;

5. l3 a chart showing the comparative torque curves of a clutchconstructed in accordance with said prior patent and when provided withthe improved porting and discharge control valve disclosed herein; and

Fig. 14 is a chart showing diagrammatically several progressivepositions of a portion of the rim of an intake control valve as comparedto corresponding positions of the outlet control slot of the dischargecontrol valve together with the corresponding progressively increasedopen areas of the inlet opening and the corre sponding uniform andprogressively decreased open areas of the outlet opening during the fullrange of movement of the flow control instrumentality from neutral tohigh position.

The preferred configurations and dimensions of the inlet and outletopenings shown in Figs. 4 and 5 are illustrative of the principles ofthe invention and, in the present instance, the dimensions or" the inletand outlet openings are those applicable to a clutch of the typedisclosed in said patent capable of transmitting 44 horsepower at 1500R. P. M.

Only certain pertinent principal elements of the clutch disclosed insaid patent are designated herein by identical reference numeralsemployed for such elements in said patent; the elements shown but notdesignated by reference numerals are the same elements as employed insaid patent.

All new elements disclosed in the drawings are designated by referencenumerals with three digits beginning with numeral 160.

The numerals of the figures disclosed in the attached new drawings whichare similar to those disclosed in said patent show in parentheses thenumeral of the corresponding figure in said patent.

Among the new improved features of the present clutch are the following:

New fluid intake port inlet openings tilt) shown in Figs. 4, 8 and 13have been substituted for the inlet openings 4 5 shown in Fig. 6 of saidprior patent;

The discharge control valve 3% may preferably be formed separately fromthe body 43 herein shown in Figs. 1, 2 and 7 operatively connected tothe body 43 by a suitable snap ring;

New fluid outlet openings 290 shown in Figs. 5, 7 and 13 are provided inthe cylindrical seat 42 in the manifold 42 under the control of thedischarge valve 300; and

The discharge control valve 3% has been completely redesigned as hereinshown in Figs. 1, 2, 7, 9 and 10; these discharge valve improvementshave therefore substantially modified the old openings 46 and 43 in themanifold 42 and valve 43 respectively and have A ec eliminated entirelythe stabilizing port 42 as more clearly shown herein in Fig. 7.

It should be noted that in the following exemplary disclosure of theintake control valves 47, the intake port inlet openings 100, and thedischarge port outlet openings 200, all dimensions shown are applicableto a clutch of the character described transmitting 44 horsepower at1500 R. P. M.

The intake valves The intake control valves 47 empolyed herein are thesame as disclosed in said patent; the effective outside diameter of therim being of an inch as shown in Fig. 3 herein.

The intake port inlet opening As disclosed herein in Figs. 4, 8 and 13,each intake port inlet opening 100 may be described as consisting of acomparatively, narrow open portion 'of A;

of an inch width extending outwardly axially from 21 semicircular edgeof of an inch radius for a length of 1 of an inch whereat this narrowopen portion merges into an open portion of increased width of K of aninch which extends outwardly axially for a length of of an inch. narrowportion of the opening is equal to substantially ,6 of the total lengthof the entire opening; the width of the narrow portion is equal tosubstantially 01: the width of the wider portion of the opening; and thewidth of the wider portion is equal to substantially V of the entirelength of the inlet opening.

The discharge port outlet opening As disclosed herein in Figs. 5, 6, 7and 13, each discharge port outlet opening 200 may be described asconsisting of an initial of an inch square opening extended outwardlyaxially into an isosceles triangular formof opening whose altitudemaybeof an inch but preferably is of an inch. In other words,

the altitude of the isosceles portion of the opening is the smoothprogressively increased range of torque controllability shown in Fig. 13wherein is also charted the comparative torque curve of a clutchconstructed with inlet and outlet port openings in accord with saidprior patent.

. In the clutch herein disclosed, the pump manifold plate 42 is providedwith a plurality of fluid intake extensions 42 each containing an intakeport 45 having an inlet opening 100 as more clearly shown herein in Fig.8.

The fluid discharge control valve The fluid discharge control valve,generally designated by numeral 300, consists of a cylindrical hollowbody 301 annularly recessed at its outer end, as at 302, for positioningwithin the triangularly shaped body 43 and. is also provided with anannular groove 303 adapted to receive therein a snap ring 303 thatoperatively ties the valve to the body 43) for concurrent movementtherewith. This valve is also provided with a. comparatively very narrowannular fluid discharge slot 304, which in actual practice has been onlyMr; of an inch in width and which extends radially inwardly from theouter periphery of the valve body only partially into the body. Threepreferably slightly inwardly converging discharge ports 305,circumferentially equally spaced, extend radially outwardly from theirIn other words, the length of the open discharge ends within the innercylindrical face of the body 301 into communication with the slot 304;the ports 305 being preferably wider axially of th valve than the slot304. The discharge control valve 300 is axially movable upon thecentrally disposed valve seat 42 of the manifold 42.

Operation tality is shown in neutral position wherein only airiscirculating through the gear pump.

As the valve control instrumentality is moved from neutral positionoutwardly, toward the left as viewed in Fig. l, the intake controlvalves 47 will be moved to uncover progressively increased open areas ofthe intake inlet openings 100 throughout the full range of theirmovements. This is graphically illustrated by the suction curve shown onthe chart in Fig. 11 and also the chart in Fig. 14. During this fullrange of movement there are being admitted into the pump circuits fluidmixtures of a progressively increased volume of oil and a progressivelydecreased volume of air. During such outward movements, the inletcontrol valves 47 first traverse the elongated narrow portions 101 ofthe inlet openings 100 and then traverse the wider'portions 102 thusevery advanced outward movement has the additive elfect of uncoveringprogressively increased areas of inlet openings until the inlet openingsare finally fully open to the, inflow of only oil.

Concurrently with the outward movements of the intake control valves 47,as above described, the discharge control valve 300 is moved outwardly.from its neutral position shown in Figs. 1 and 7 whereupon its flowcontrol slot 304 is caused first to traverse the rectangular outletareas 201 of the discharge outlet openings 200 and finally theprogressively decreased triangular areas 202 of the outlet openings.This is graphically illustrated by the discharge curve shown on thechart in Fig.

ll and also the chart in Fig. 14. It will now be evident that duringsuch progressive outward movement, the discharge control valve 300constantly maintains predeterelements of the concurrently movable intakeand discharge valves are the outer circumferences 47 of the inrelatively smalier or larger clutches these. dimensions wouldaccordingly be subject to variations without departing from the basicrelative configurations of the fluid circuit inlet and outlet openingswhich I have found function in their coaction to produce the desiredgreater range and smoothness of controllability.

I claim: a

1. In a clutch of the character described having a plurality of fluidintake circuits and a plurality of fluid discharge circuits each havingrespectively an inlet opening and an outlet opening, including anaxially movable fluid flow control instrumentality provided with aplurality of intake control valves for said inlet openings and a singledischarge control valve for said outlet openings, said valves beingconcurrently movable during axial movement of the instrumentality andsaid inlet and outlet openings being of such configurations and soarranged axially of the clutch that in the progressive axial movement ofthe instrumentality each intake control valve is progressively movableto uncover a progressively in creased open area of its correspondinginlet opening throughout its entire range of movement Whilesimultaneously said discharge control valve traverses uniform open areasof said outlet openings during a predetermined initial portion of itsrange of movement and thereafter traverses progressively decreased areasof said outlet openings during the remaining portion of its range ofmovement until fluid discharge therefrom is completely arrestedwhereupon the intake circuit inlet openings are fully open to the inflowof oil.

2. In a clutch of the character described as set forth in claim 1wherein said discharge control valve traverses said uniform open areasof said outlet openings during substantially one-half of its range ofmovement.

3. In a clutch of the character described as set forth in claim 1wherein said discharge control valve traverses said uniform open areasof said outlet openings during an initial portion of not less thanthree-eights of its entire range of movement.

4. In a clutch of the character described as set forth in claim 1wherein each of said inlet openings consists of a comparatively narrowopen portion that is initially traversed by its corresponding intakecontrol valve and that merges into a wider open portion, the length ofsaid narrow portion being equal to substantially two-fifths of the totallength of the entire inlet opening.

5. In a clutch as set forth in claim 4 wherein the width of said narrowportion of each inlet opening is equal to substantially four-sevenths ofthe width of said wider portion of the inlet opening.

6. In a clutch as set forth in claim 5 wherein the width of said widerportion of each inlet opening is equal to substantially seven-twentiethsof the entire length of the inlet opening.

7. In a clutch of the character described having a plurality of fluidintake circuits and a plurality of fluid discharge circuits each havingrespectively an inlet opening and an outlet opening, including anaxially movable fluid flow control instrumentality provided with aplurality of intake control valves for said inlet openings and a singlecylindrical discharge control valve for said outlet openings, saidvalves being concurrently movable during axial movement of theinstrumentality whereby each intake control valve is progressivelymovable to uncover a progressively increased open area of itscorresponding inlet opening throughout its entire range of movementwhile simul taneously said discharge control valve progressivelytraverses the plurality of outlet openings, each outlet openingconsisting of an open initially traversed portion of uniform widthextended axially outwardly of the manifold in anisosceles-triangular-shaped open terminal portion.

8. In a clutch as set forth in claim 7 wherein saidisosceles-triangular-shaped terminal portion of each outlet opening isnot axially less in length than the axial length of said portion ofuniform width.

9. In a clutch as set forth in claim 8 wherein the base of saidisosceles portion of each outlet opening is equal in length to the axiallength of said portion of uniform width.

10. In a clutch as set forth in claim 9 wherein said discharge controlvalve consists of a cylindrical hollow body provided with a narrowannular fluid discharge slot extending radially inwardly from the outerperiphery of said valve body only partially into said body, a pluralityof discharge ports, circumferentially equally spaced, extending radiallyinwardly from said slot to their respective discharge openings withinthe inner cylindrical face of said body.

ll. In a clutch as set forth in claim 10 wherein said circumferentiallyequally spaced ports are wider axially of the valve than said annulardischarge slot.

12. In a clutch of the character described as set forth in claim 1wherein said discharge control valve consists of a tubular body providedwith a narrow peripheral fluid discharge slot extending inwardly fromthe outer periphery of said body only partially into said body, and aplurality of circularly equally spaced discharge ports extendinginwardly from said slot to their respective discharge openings withinthe inner face of said tubular body.

13. In a clutch of the character described as set forth in claim 7wherein said discharge control valve consists of a cylindrical hollowbody provided with a narrow annular fluid discharge slot extendingradially inwardly from the outer periphery of said valve body onlypartially into said body, a plurality of discharge ports,circumferentially equally spaced, extending radially inwardly from saidslot to their respective discharge openings within the inner cylindricalface of said body.

No references cited.

